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Automatic control of tool width
Figure 13: Splice-welding machine with closed tooling The width of the splice nugget has to be adjusted to the total cross-section of the wires to be welded together. This is done manually, i.e. by adjusting the corresponding anvil parts to the specific width or by using a stepper motor, which will control the movement of the anvil to the required width. In figure 14, ultrasonically-welded wires with different cross-sections are depicted. Since the welding force is introduced perpendicularly to the transducer axle during ultrasonic metal welding, deflection of the sonotrode is inevitable. These forces act upon the transducer system and its mounting. Deflections at the sonotrode work area during the welding process are undesirable since this may lead to mechanical and/or procedural faults of the welding tools. In the first design example (spot-welding equipment), the whole ultrasonic transducer system is moved.
Figure 14: Welded splice nuggets A different mounting is designed using the nodal surface of the sonotrode. It is preferred that the sonotrode is clamped at its exact nodal point by high-tensile threaded pins (figure 15). Clamping requires special experience The clamping of the high-frequency oscillating transducer system requires special experience, both to determine the location of the nodal area as well as the transducer's maximum amplitude output.  This is the only location where the whole transducer system can be supported and clamped. Residual energy or residual forces are minimal in this area, but they still need to be controlled.
Figure 16: Ultrasonic splice-welding machine with electronic quality control In doing so, the body of the sonotrode is supported somewhere at the middle of its length and therefore the bending couples and deflection will be negligible. Figure 16 shows ultrasonics splice-welding equipment with an electronic quality monitor.
Seam-welding equipment
Figure 17: Ultrasonic transducer system for seam-welding machine Simultaneously with the rotary movement of the sonotrode, a horizontal movement is carried out. The machine has to be designed so that the welding pressure is kept constant throughout the welding process. Generally speaking, the parts to be welded are firmly held or clamped in the machine to prevent any uncontrollable movement and thus insure proper welding quality.
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With the second type of machinery (wire-splice-welding equipment), the transducer system remains firmly clamped onto the body of the welding unit, and only the non-oscillating parts of the machinery are moved.
The splice-welding equipment in figure 15 has made it possible to accommodate the sonotrode itself in its nodal point and to fix it there, instead of fixing the transducer system between booster (amplitude transformer) and sonotrode.
Power loss must be kept at a minimum in order to prevent a temperature build-up in the system. This would result in a drift of the resonance frequency and again create a power loss.
